1. Field of the Invention
The present invention generally relates to mobile communication terminals and, more particularly, to a mobile communication terminal such as a portable telephone set or a PHS terminal, capable of automatically or semi-automatically executing a communication service in a mobile communication system according to the location and the condition.
Execution of communication services that a mobile common carrier offers corresponds closely to a location and a condition in which a mobile communication terminal is used. For example, a user may not want a business-related call to arrive in a private time. Conversely, the user may not want a private call to arrive during work. Further, the user may usually want a call to arrive with a ringing tone, but may also want a call to arrive with a vibrator alarm or in an answer phone mode while the user is in a meeting room or a library. However, when such a setting is executed manually, a call which otherwise should arrive may not arrive, or a call may arrive with a ringing tone while the user is in a meeting room or a library, due to an error in the operation or a failure to provide the appropriate setting.
Recently, the area covered by one base station has become small as in a PHS system, so that it has become possible to automatically or semi-automatically offer communication service that depends on a place and condition in which a user is in, to a mobile communication terminal.
2. Description of the Related Art
A car navigation system is well known as a mobile communication system in which a mobile common carrier offers communication service to a mobile user, based on location information. A car navigation system provides communication service such that the current location information of a mobile user is detected, and the current location information is transmitted to a mobile common carrier. The mobile common carrier retrieves map information and transmits the map information to the mobile user.
A similar system is known wherein a mobile communication terminal detects reported location information reported by a base station, the mobile communication terminal supplies the reported location information to a mobile communication network so that the mobile common carrier provides communication service accordingly.
Such systems not only provide map information but also information and communication service relating to the location of the mobile communication terminal. For example, information relating to local facilities and service programs may be provided. The mobile communication terminal can request expansion or update of the information in a database provided by the mobile common carrier. With this, the mobile common carrier can provide the latest information that meets the demands of the users. The mobile common carrier maintains a database on its own in order to manage the reported location information and the communication services to be executed.
In a mobile common carrier in which the area indicated by the reported location information from a mobile communication terminal is identified so that a setting of a mobile communication terminal is changed automatically, the following problems exist.
Because the reported location information is introduced in order to facilitate management of a location of a terminal in a mobile communication network by a mobile common carrier, it has nothing to do with community. Accordingly, a location managing host, a manager in a mobile communication system, should generate a database of map information that relates the community to the area indicated by position information of the terminal managed by the mobile communication network. However, there is a problem in that much storage capacity is needed if the position information from different mobile common carriers is introduced in the map information and if the communication service preset individually by users is managed by a switch.
It is difficult for a switch to centrally determine a communication service because the significance of an area indicated by the reported location information submitted by a mobile communication terminal is different from one individual to another and should be preset by an individuals own initiative.
As the area indicated by the reported location information becomes smaller, the volume of reported location information that a mobile communication terminal detects increases. As a result, the frequency with which the mobile communication terminal reports the reported location information to the mobile communication network increases, so that the traffic of the location information supplied from the mobile communication network to the location managing host increases.
The mobile communication network of a mobile communication system usually manages information related to an area in the form of several sets of reported location information put together, instead of the reported location information itself, in order to prevent an increase in the traffic of the reported location information from mobile communication terminals. Therefore, it is not possible for the managing host to perform detailed location management if the location information managed by a mobile communication network is used. Accordingly, the map information that relates the location indicated by the location information to the community cannot be properly generated.
Assuming a case in which the location managing host receives location information via a switch, and assuming that the mobile communication networks of several mobile common carriers are to be used, each communication network needs to have facilities to transmit location information to the location managing host, which is difficult to implement.